Bellringer – September 23, 20141) Draw the following leaf and fill in the blanks

for the 5 arrows.

2) In what organelle does photosynthesis take place?

3) Try and write the FULL and BALANCED equation for photosynthesis

Photosynthesis:Life from Light and Air

AQUAPONICS

Plants are energy producers• Like animals, plants need energy to live• Unlike animals, plants don’t need to eat

food to make that energy• Plants make both food & energy– animals are consumers– plants are producers

The Process That Feeds the Biosphere

Photosynthesis the process that converts solar energy into chemical energy

Who or What? Plants and other autotrophs

They are producers of the biosphere

Plants form the base of most food chains

Plants, some bacteria and algae are photoautotrophs Use energy of sun to make organic molecules from

H2O and CO2

Some worms and bacteria are chemoautotrophs Use energy from chemicals to make organic

molecules

2 Types of Autotrophs

PhotosynthesisOccurs in plants, algae, certain other protists, some prokaryotes

They feed not only themselves, but the entire living world. (a) On land, plants are the predominant producers of food. In aquatic environments, photosynthetic organisms include (b) multicellular algae, such as this kelp; (c) some unicellular protists, such as Euglena; (d) the prokaryotes called cyanobacteria; and (e) other photosynthetic prokaryotes, such as these purple sulfur bacteria, which produce sulfur (spherical globules)

(a) Plants

(b) Multicellular algae

(c) Unicellular protist10 m

40 m(d) Cyanobacteria

1.5 m(e) Purple sulfur

bacteria

Figure 10.2

The Equation for Photosynthesis

Photosynthesis converts light energy to the chemical energy of food

Photosynthesis is summarized by this

Overall chemical equation

6 CO2 + 6 H2O + Light energy C6H12O6 + 6 O2

Using light & air to grow plants

6CO2 6H2O C6H12O6 6O2sunenergy

+ ++

glucose + oxygencarbondioxide

sunenergy+ water +

(ATP)

– using sun energy to make glucose – Then use glucose to generate ATP– using carbon dioxide from air & water from roots to make

sugar– Takes place in chloroplast– allows plants to grows and do work– makes a waste product

• oxygen

Chloroplasts: The Sites of Photosynthesis in Plants

The leaves of plants-THEY’RE GREEN!! major sites of photosynthesis, also

occurs in stems.

Chloroplasts Stroma

Dense fluid within chloroplast Dark reaction occurs here

Thylakoids Membranous sac (or “coin”) in stroma Light reactions occur here

Grana (granum = singular) Stack of thylakoids (“coins”)

The Nature of Sunlight Light

a form of electromagnetic energy, which travels in waves and particles (called photons)

Wavelength distance between crests of waves

Determines type of electromagnetic energy (wavelength & energy are inversely proportionate)

The electromagnetic spectrum The entire range of

electromagnetic energy, or radiation

Gammarays X-rays UV Infrared

Micro-waves

Radiowaves

10–5 nm 10–3 nm 1 nm 103 nm 106 nm1 m

106 nm 103 m

380 450 500 550 600 650 700 750 nm

Visible light

Shorter wavelengthHigher energy

Longer wavelengthLower energy

Color we SEE = color most reflected by pigment; other colors (wavelengths) are absorbedBLACK all colors are reflected

Light

ReflectedLight

Chloroplast

Absorbedlight

Granum

Transmittedlight

How do the light reactions capture solar energy?

Photosynthetic Pigments molecules that absorb visible light different pigments absorb different

wavelengths of light Many different pigments used in

light reactions of photosynthesis

Primary vs. Accessory Pigments

Primary PigmentChlorophyll a (most abundant)

Accessory (Antennae) Pigments

Chlorophyll bAnthocyaninsXanthophyllsCaratenoids

Photosynthetic pigments• Primary pigment = chlorophyll a  – takes direct part in light reactions

• Accessory pigments• protect chlorophyll a from UV light damage• absorb light at wavelengths that are not absorbed by chlorophyll a• Transfer energy to chlorophyll a help broaden the absorption spectrum for photosynthesis (act as “antennae”)

The Two Stages of Photosynthesis: A Preview

• The Light reactions•NEEDS LIGHT•Light Dependent Reactions

• The Calvin cycle•A.K.A- Dark Reactions or Light Independent Reactions •DOES NOT NEED LIGHT

The Light Reactions

Occur in the grana (& thylakoids)

Convert solar energy to chemical energy

Chlorophyll absorbs solar energy Splits water release O2 (a by-product) produce ATP and NADPH (chemical energy)

The Calvin Cycle

Occurs in the stroma (gel of chloroplast)Forms SUGAR (glucose) from carbon dioxide

Carbon fixation occurs (CO2 organic carbon)

Uses ATP for energy and NADPH to carry electrons

What do plants do with the glucose?

• Use it! – They can use cellular respiration to

break glucose down and make ATP (cellular energy)

• Store it!– They can string together lots of

glucose molecules to form starches (stored energy) or cellulose (strong fibers that support cell walls)

An overview of photosynthesis

H2O CO2

Light

LIGHT REACTIONS

CALVINCYCLE

Chloroplast[CH2O](sugar)

NADPH

NADP

ADP+ P

O2

ATP

Photosynthesis

This is the equation you are used to seeing, but this is not the whole story…

+ water + energy glucose + oxygencarbondioxide

6CO2 6H2O C6H12O6 6O2lightenergy

+ ++